CN101243269A

CN101243269A - Pivoting mechanical tensioner with cross strand damping

Info

Publication number: CN101243269A
Application number: CNA2006800294687A
Authority: CN
Inventors: G·马克利; M·维斯腾; J·卡普
Original assignee: BorgWarner Inc
Current assignee: BorgWarner Inc
Priority date: 2005-08-15
Filing date: 2006-07-25
Publication date: 2008-08-13
Anticipated expiration: 2026-07-25
Also published as: JP5127712B2; WO2007021471A1; US20070037646A1; JP2009505021A; CN101243269B; US7476168B2; EP1915550A1; EP1915550B1; DE602006015483D1

Abstract

A closed loop chain tensioner system having a drive sprocket, one or more driven sprockets, a first mechanical tensioner located adjacent a slack strand and a second mechanical tensioner located adjacent a tight strand. Each tensioner is independently pivotally mounted to the engine block. The mounting point may be located at any point along the length of each tensioner. The tensioners are then linked to each other by a rigid, solid link. This solid link enables the tensioners to act in unison, thus providing damping across both strands of chain in response to engine torsional variations.

Description

Pivoting mechanical tensioner with cross strand damping

To quoting of related application

The application with submit to simultaneously, that name is called the application of " the long formula mechanical tensioner that has compliant blade spring " is relevant.By reference above-mentioned application is combined in this.

Background of invention

Invention field

The present invention relates to the chain tensioning device field.More particularly, the present invention relates to a kind of stretcher with damping effect.

Description of Related Art

A kind of tension device is a kind of control gear that is used as power chain or similar actuating unit between some sprocket wheels when chain moves.This device in, chain is sent to driven shaft with power from driving shaft, like this part of chain be relax and a part is tight.Generally speaking, for the drop out of gear that prevents noise, slippage or sprocket occurs under the situation of toothed chain closes, the tension force that applies on chain and keep to a certain degree is important.For the camshaft of the chain transmission on the internal-combustion engine, prevent that above-mentioned slippage is even more important, this is because beating of tooth can cause losing camshaft timing, thereby might cause damage, or causes internal-combustion engine not work.

Yet in the harsh and unforgiving environments of internal-combustion engine, various factors can both cause the fluctuation of chain tension.For instance, can cause chain tension between too high or too low level, to change at the greatest differences aspect thermal expansion coefficient and the temperature variation between the different parts of internal-combustion engine.In long-term using process, the wearing and tearing of dynamic transfer system part can cause the reduction of chain tension.In addition, the torsional vibration that causes of camshaft and bent axle also can cause sizable variation of chain tension.The motor reversing that for example occurs when engine shutdown or starting failure also can cause the fluctuation of chain tension.Owing to above reason, wish to have a kind of mechanism to eliminate crossing high tension and guaranteeing the necessary tension force of chain slack-side on the chain tension side.

Blade tensioner means the stretcher that is unlikely to a certain chain of normally used control under the situation of the one or more springs of excessive warpage or belt at load fluctuation.For the effective backward that limits tension device or the stroke of tensioning not, the ratchet of a band backlash usually is housed on the stretcher.

Fig. 1 illustrates a kind of chain drive system of prior art, and this system has a blade tensioner and a guide.A closed loop chain is centered around on drive sprocket 12 and the driven sprocket 10.Keep advance in,

sprocket wheel

10 and 12 quickens independently of one another or slows down.A fixed guide 14 is connected on the carriage 7 of chain 8 tension section.Relative with this fixed guide 14 is a stretcher 16 on the chain slack strand, and the latter is fixed on the carriage 7 semi-rigidly, and makes the tension section of chain be subjected to bias voltage.The carriage that a plurality of bolts 18 will comprise stretcher 16 and guide 14 is fixed on (not shown) on the engine cylinder.

When drive sprocket 12 acceleration or driven sprocket 10 decelerations, in the tension section meeting produce power ripple or the higher local load of chain, this energy waves or local load move towards another sprocket wheel from the altered sprocket wheel of speed.Chain 8 attempt with the shortest distance (being straight line) across with distance between initial sprocket wheel and the contacted chain of other sprocket wheels are connected.Energy is absorbed by this end after it arrives the end of guide 14 by all chain link transmission on the free section of chain.Owing to absorb high local load continuously, significant wearing and tearing are born in the end of guide 14.Although depend on that stretcher keeps chain not have lax good degree and stretcher and has this Wave energy of how many vibration dampings and may can not take place,, if it occurs in the slack strand of chain, energy waves also can exist and will show identical feature.

The a solution that reduces the load in the chain transmission system that occurs in prior art is to increase vibration damping for stretcher.A problem relevant with stretcher being increased required vibration damping is that it can cause the control of loss of chain if this stretcher is softened significantly, is used for applying just that enough power provides suitable chain control because stretcher is a specialized designs.Shown in other solutions such as the U. S. Patent the 5th, 797,818 and the 6th, 322, No. 470 and US publication 2002/0045503 and the 2005/0085322nd.

5,797, No. 818 U. S. Patents have disclosed and have a kind ofly reduced the chain assemblies of noise and vibration in the chain slack-side, and it comprises a blade shoe, a spring and an elastic vibration clamper.This bearing is by being pivotally mounted on the tensioner.Spring be installed on the bearing and to bearing to chain row replacement bias voltage.Elastic vibration clamper is installed between tensioner and the spring, the vibration that produces during with the action of help control valve.

6,322, No. 470 U. S. Patent has disclosed a kind of stretcher that comprises a pair of swinging arm, and this is used for two different chain segment of the same chain of tensioning simultaneously to swinging arm.A lever that has fixing pin is between these two sections.Two arms are stretched over the chain segment outside and are carrying bearing, orientate as with contacted these bearings of the external lateral portion of chain to be pivotally mounted on the fixing pin.The rotation of lever causes that fixing pin laterally moves and these arms inwardly draw, and tension force is applied on each section of chain simultaneously.In other words, the high loading of chain one side attempts to be delivered to the opposite side of chain, but the final balance that always reaches of load.

US publication 2002/0045503 has disclosed a kind of chain tensioning device that has a blade and spring assembly.This blade has one first end and one second end.This first end is limiting a hub.This hub is connected on the intermediate portion and one first end wall of blade shoe, and defines a hole of accepting a single pin, and this list is sold blade pivot is connected on the mounting bracket.

Fig. 2 illustrates the pivoting chain guide and the tensioner assembly of US publication 2005/0085322.It is made up of a chain guide 124 and a stretcher, the two separately with a double-stranded wheel system in one of two sections of a closed loop chain 108 contact, this chain 108 is looped around on drive sprocket 112 and the driven sprocket 110.This stretcher and chain guide all are connected on the carrier plate 122, and this carrier plate pivots around an independent mounting points 120.

As shown in Figure 3, the chain tension system of a routine by on two functions independently leaf spring stretcher 306 and 306a form, they lay respectively on two sections of chain 300.These two stretchers that work respectively comprise

pallet body

307 and 307a separately, and two pallet bodies separately Bao Na chain guide 308 and 308a.In each

pallet body

307 and 307a, has a leaf spring at least, be designated 510 (see figure 4)s, so that force chain guide 308 to enter compulsory the contact with each section of chain 300, and each mechanical spring stretcher 306 and 306a are adjacent with these sections with 308a.In this conventional system, the operation of each mechanical spring stretcher is separate.Each mechanical spring stretcher is fixedly mounted on the engine cylinder (not shown) by fixing device 312 (for example, it can be bolt or press-fit pin).For tension force provided between the slack strand of regulating chain 300 and the tension section unique motion comes from these leaf springs.

Summary of the invention

The present invention includes the moving system of a kind of power transmission, this system has a drive sprocket, one or more driven sprocket, is positioned near one first mechanical tensioner of slack strand and is positioned near one second mechanical tensioner of tension section.By adopting compliant blade spring, each mechanical tensioner all can provide slackness control.

Each stretcher pivotally is fixed on the engine cylinder by dividing other erecting device.So these stretchers are connected with each other by a rigidity, firm company joint, this companys joint makes each stretcher can control forward and backward hinged of chain between tensioning and relaxation condition harmoniously, so the damping of striding two sections on chain is provided.

Description of drawings

Fig. 1 illustrates the schematic representation of chain tensioner system of a kind of prior art of the common bracket with firm installation.

Fig. 2 illustrates the schematic representation of a kind of chain tensioner system of the pivoting point with independent central authorities' installation.

Fig. 3 illustrates a schematic representation of the two stretchers that independently work.

Fig. 4 illustrate a kind of common blade stretcher the part of an excision.

Fig. 5 illustrates a chain guide of the stretcher that is used for Fig. 4.

Fig. 6 illustrates a front perspective view of interconnected dual tensioner system of the present invention.

Fig. 7 illustrates an isometric view of of the present invention pair of tensioner system, has wherein removed a mechanical blade tensioned device so that illustrate and has been used for pivotal mounting and the fixing device that rigidity connects joint.

Fig. 8 illustrates one second embodiment of the present invention.

Fig. 9 illustrates one the 3rd embodiment of the present invention.

Detailed description of the invention

As shown in Figure 6 and Figure 7, the present invention includes a continuous chain loop drive system with chain 500, drive sprocket 502, one or more driven sprocket 504 and a 504a and a pair of mechanical tensioner 506 and 506a.Each mechanical tensioner is made up of

pallet body

507 and 507a and chain guide element separately 508 and 508a, and each chain guide has a

chain slip surface

509 and 509a (as shown in Figure 5).One section of the chain 500 that these

chain slip surfaces

509 and 509a are adjacent with each mechanical tensioner is in sliding contact.

The all springs that are expressed as 510 (Fig. 4) generally can provide and impel

chain guide element

508 and 508a and chain 500 to be in the required power of pressure sliding contact.Leaf spring 510 is rectangles of the elongation of curling on length under its free state.In preferred tensioner shown in Figure 4, leaf spring 510 applies a power to the downside of supporting element 505, and this supporting element is similarly the rectangular configuration of an elongation, can make it can provide the material of spring tension to make by any.The power of

chain guide element

508 and 508a being pressed to their corresponding chain segment comes from leaf spring 510.The spring tension that is provided by supporting element 505 only need be enough to cardinal principle is equally transmitted leaf spring 510 along the length of

chain guide element

508 and 508a power.

Each

mechanical tensioner

506 and 506a all by be designated respectively generally 512 and the independent erecting device (such as bolt, screw or press fit pivot pin) of 512a be fixed on (not shown) on the engine cylinder.In one first embodiment as shown in Figure 6, this erecting device provides a pivoting point for its corresponding mechanical tensioner, and is positioned on the approximately identical corresponding position along the length direction of mechanical tensioner respectively.Shown in erecting

device

512 and 512a be positioned at one first end of each mechanical tensioner of the most close drive sprocket 502.This erecting device also can be positioned at along on other aspects of mechanical tensioner 506,506a length, such as any point along each

pallet body

507 and 507a length.Show an alternative site that is used for erecting device at 512c and 512d among Fig. 6.

As shown in Figure 6,

pivot device

514 and 514a lay respectively at the corresponding second end place of each pallet body 507 and 507a.Each

pivot device

514 and 514a are respectively by

locking device

515 and 515a or similar device or entered dowel fixes in the hole of each

pallet body

507 and 507a respectively by press fit on second end of its corresponding pallet body 507 and 507a.One end of a firm stiff chain relay part 516 is connected on each pivot device 514 and the 514a, coordinates the motion of corresponding second end of these

mechanical tensioners

506 and 506a thus.

Fig. 7 illustrates an isometric view of the chain tensioning device of Fig. 6, has wherein removed a stretcher 506 so that erecting device 512 is shown and the more details of pivot device 514.

When drive sprocket 502 or when one of driven

sprocket

504 and 504a slow down at least, a section (being tension section in this example) of chain 500 will attempt with short as far as possible distance (being straight line) cross over and the contacted chain link of initial sprocket wheel to the distance between another sprocket wheel.This special exercise of not shown chain 500.This energy waves or high local load will apply power for the end of corresponding mechanical tensioner (being stretcher 506 in this example) at pivot device 514 places away from chain 500.End by the fixing stretcher of erecting device 512 keeps pivotally being fixed on the motor.

Simultaneously, along with a chain segment is tensioned, another relative section becomes slack.Yet because link 516 is connected on the corresponding mechanical tensioner (being stretcher 506a in this example), this link 516 will be towards the end of the slack strand direction pulling mechanical tensioner 506a of chain 500, thus this slack strand of tensioning basically.

Periodicity tensioning relative to each other of each section of chain and the lax tolerance to a certain degree that provides are provided this of the motion of tension section and slack strand.By connecting the relative movement of each chain segment, produced a kind of damping effect.The vibration that stands by one of chain segment with reverse momentum by this energy being connected with the opposite backward energy momentum that chain segment stood and being neutralized basically.

As indicated above, the erecting device 512 of each

mechanical tensioner

506 and 506a and 512a can lay respectively at the end near two mechanical tensioner of drive sprocket 502, for convenience's sake, are referenced herein as their corresponding first ends.Further disclose as mentioned, according to the selection in the design, erecting device also can be positioned at along any point on pallet body 507 and the 507a length.The diverse location that many variablees in whole chain transmission system can cause being not only erecting device 512,512a and also have

pivot device

514 and 514a and connected element 516.

As shown in Figure 8, different functional parameter and designing requirements may make it link 516 must be positioned near each mechanical tensioner 506 of drive sprocket 502 and second end of 506a.In this second embodiment, first end of each mechanical tensioner is fixedly installed on the engine cylinder by erecting

device

512 and 512a and is positioned near the (not shown) drive sprocket.

Fig. 9 illustrates one the 3rd embodiment.In this embodiment, the first end 516a of link 516 is fixed on the terminal opposite end of the first stretcher 506a and this first stretcher that is fixed to (not shown) on the motor body by erecting device 512a by pivot.The second end 516b of this link 516 by pivot device 514 pivots be fixed on along on second stretcher, 506 length roughly near midpoint.

Leaf spring 510 shown in Figure 4 is indicated as than chain guide 508 has a shorter length.Yet, in the scope that the present invention considers, also can use other leaf spring configurations, such as the configuration that comprises the leaf spring that equals whole chain guide 508 length substantially.Equally, a plurality of short blade spring 510 can be arranged in proper order along pallet body 507 length.

Furthermore, the strength capabilities of each leaf spring of every kind of

mechanical tensioner

506 and 506a can be identical or different.If the spring that is equipped with in first stretcher (for example, stretcher 506) is more weak with respect to the spring of the interior outfit of second stretcher (506a), then all controls of lax chain all are sent on the second stretcher 506a by link 516.In this configuration, first stretcher 506 plays a guide, and this guide has the ability to follow a uncontrolled chain 500 from its normal route, thereby improved vibration damping is provided.

In addition, according to the requirement of the design parameter of the power transmission catenary system of the tension device of the present invention of packing into therein, these stretchers 506 both can have identical length with 506a also can have different length.

Therefore, be to be understood that these embodiments of the present invention described here are just in order to illustrate the application of the principles of the present invention.Details in this illustrative embodiment of addressing is not to be intended to limit the scope of claim, and these claims itself have been enumerated and have been considered to feature essential to the invention.

Claims

1. a chain guide and tensioner assembly that is used to consist essentially of the circulation link chain loop of two chain segment that drive sprocket is connected with at least one driven sprocket transmission ground comprises:

First stretcher comprises first pallet body and first chain guide, and described first chain guide has the first chain slip surface, is used for contacting of described two chain segment;

Second stretcher comprises second pallet body and second chain guide, and described second chain guide has the second chain slip surface, is used for contacting the another one of described two chain segment;

Rigid connector with two ends, first end are fixed on described first stretcher pivotally and second end is fixed on described second stretcher pivotally;

Wherein, described first stretcher is fixed on first position on the motor body by first erecting device, and described second stretcher is fixed on second position on the described motor body by second erecting device.

2. chain guide as claimed in claim 1 and tensioner assembly is characterized in that, described first stretcher further comprises at least one leaf spring and supporting element.

3. chain guide as claimed in claim 1 and tensioner assembly is characterized in that, described second stretcher further comprises at least one leaf spring and supporting element.

4. chain guide as claimed in claim 1 and tensioner assembly, it is characterized in that, described first stretcher further comprises at least one first leaf spring and first supporting element, and described second stretcher further comprises at least one second leaf spring and second supporting element.

5. chain guide as claimed in claim 4 and tensioner assembly is characterized in that, described first leaf spring presents and the identical strength capabilities of described second leaf spring.

6. chain guide as claimed in claim 4 and tensioner assembly is characterized in that, described first leaf spring presents and the different strength capabilities of described second leaf spring.

7. chain guide as claimed in claim 1 and tensioner assembly is characterized in that, described first erecting device and described second erecting device are positioned at the end of wherein each pallet body of wherein each stretcher of approaching described drive sprocket.

8. chain guide as claimed in claim 1 and tensioner assembly is characterized in that, described first erecting device and described second erecting device are positioned on about corresponding point along the longitudinal length of each stretcher wherein separately.

9. described chain guide as claimed in claim 1 and tensioner assembly is characterized in that, described first erecting device and described second erecting device are positioned at the end of wherein each pallet body of wherein each stretcher of approaching described driven sprocket.

10. chain guide as claimed in claim 1 and tensioner assembly, it is characterized in that, first end of described rigid connector is attached on the position on described first stretcher, and described position is different from the position that second end of described rigid connector adheres on described second stretcher.

11. chain guide as claimed in claim 1 and tensioner assembly is characterized in that, described first stretcher and described second stretcher are measure-alike.

12. chain guide as claimed in claim 1 and tensioner assembly is characterized in that, described first stretcher is different with the described second stretcher size.